1. Technical Field
The present invention relates to a display manufacturing apparatus and a display manufacturing method for manufacturing a variety of displays such as a color filter for a liquid crystal display device, an electroluminescent display device and the like by discharging liquid material.
2. Background Art
In order to manufacture a color filter for a liquid crystal display device, an electroluminescent display device or a plasma display device, there has been appropriately used an injection head (for example, an ink jet head) by which a liquid state material (liquid material) can be discharged in a liquid state. In a display manufacturing apparatus using an injection head, for example, a color filter is manufactured by injecting liquid material discharged out of nozzle openings to a plurality of pixel regions provided on the surface of a substrate. However, a variation in the characteristics at every nozzle opening may results in defects such as color nonuniformity or decoloring at the pixel regions. Also, when the defects occur, liquid material is discharged to the defective pixel regions for restoration. For example, Japanese Unexamined Patent Application Publication No. 7-318724 suggests a technique to restore the defects by discharging a certain color of ink drops to the non-uniformly colored or decolored portions of a color filter.
On the other hand, in case of the manufacturing apparatus disclosed in the above publication, an injection head having a heat-generating element has been used. The injection head of this type discharges ink drops by causing the heat-generating element to generate heat and boiling the ink in a pressure chamber. In other words, a liquid state ink is pressurized by boiling bubbles and discharged out of the nozzle openings. Therefore, the amount of discharged ink is determined mainly by the volume of the pressure chamber and the area of the heat-generating element. Also, since it is difficult to control the volume of the boiling bubbles with high precision, it is also difficult to control the amount of discharged liquid with high accuracy by adjusting the quantity of supply power.
Therefore, in order to make a restoration of the non-uniformly colored or decolored portions by filling up an extremely small amount of liquid material, it is necessary to include exclusive nozzles or heads used only for restoration, as disclosed in Japanese Unexamined Patent Application Publication No. 8-82706 or Japanese Unexamined Patent Application Publication No. 8-292311, for example.
However, when the exclusive nozzle or head is separately provided, the structure of the apparatus gets so complex as to result in an increase in the number of parts. Further, it may bring about additional problems in common use.